The polar vortex is a system of wintertime winds.

极地涡旋是冬季风形成的一个风系。

There was a period of excessive warmth which melted some of the polar ice.

有段时期温度过高，融化了极地的部分冰层。

Polar bears live in the Arctic.

北极熊生活在北极。

It's located in the moon's South Polar Region.

它位于月球的南极区域。

On Wednesday, a polar wind brought bitter cold to the Midwest.

周三，一股极地风给中西部地区带来了刺骨的严寒。

I'm back in Finland with the snow, reindeers, and polar bears.

我回到了芬兰，那里有雪、驯鹿和北极熊。

If you live near the Arctic Circle, hug the closest polar bear.

如果你生活在北极圈附近，请拥抱离你最近的北极熊。

With the temperature rising, polar ice will melt at a faster rate.

随着温度的上升，极地的冰会以更快的速度融化。

This is the result of the four polar bonds clustering symmetrically in space.

这是四个极性键按空间对称聚集的结果。

Biologists calculate that there are about 20,000-25,000 polar bears worldwide.

生物学家估计，全世界大概有2万至2万5千只北极熊。

Second, the polar atmosphere is thin, so little energy is required to warm it.

其次，极地的大气层很薄，所以加热它所需要的能量很少。

Wildlife like polar bears and walruses that depend on sea ice to live is also in danger.

像北极熊和海象这样依靠海冰生存的野生动物也处于危险之中。

Global warming has posed a serious threat to the survival of animals such as polar bears.

全球变暖对北极熊等动物的生存造成了严重威胁。

When snowfalls on high mountains or in polar regions, it may become part of the glacial system.

当雪落在高山或极地地区时，它可能成为冰川系统的一部分。

Like brown bears and polar bears, sloth bears may have evolved in an environment with few trees.

和棕熊和北极熊一样，树懒熊可能是在树木稀少的环境中进化而来的。

The Canadian Arctic is a vast, treeless polar desert that's covered with snow for most of the year.

加拿大的北极是一个广阔的、没有树木的极地沙漠，一年中大部分时间都被雪覆盖着。

Although polar bears' locomotion is similarly inefficient, polar bear cubs walk along with their mother.

尽管北极熊的运动能力同样低下，北极熊幼崽还是和妈妈一起前行。

The polar bear is the largest terrestrial carnivore, being more than twice as big as the Siberian Tiger!

北极熊是陆地上最大的肉食性动物，比西伯利亚虎都要大两倍多！

Adaptations to the regular change of seasons in the temperate and polar regions may be relatively simple.

在温带和极地地区适应季节的规律变化可能是相对简单的。

There're lots of animals in the North Pole, for example, whale, polar bear, and sea dog, and I like polar bear best.

在北极有很多动物，比如鲸鱼、北极熊、海狗等，而我最喜欢北极熊。

Glaciers are sometimes classified by temperature as faster-flowing temperate glaciers or as slower-flowing polar glaciers.

冰川有时按温度分为流动较快的温和冰川或流动较慢的极地冰川。

Scientists have long suspected that several factors lead to greater temperature swings at Earths polar regions than elsewhere.

长期以来，科学家们一直怀疑有几个因素导致了地球极地地区比其他地区更大的温度波动。

The nomads' lifestyle was the polar opposite of collectivization.

游牧民的生活方式同集体化的生活方式刚好相反。

Polar bears need the ice.

北极熊需要冰。

Polar bears are in great danger.

北极熊处于极度危险之中。

Polar bears like hunting for seals to eat.

北极熊喜欢捕食海豹。

They have pushed down the number of polar bears and seals while polar bears depend on sea ice for hunting seals.

它们导致了北极熊和海豹数量的减少，而北极熊依靠海冰捕食海豹。

Polar bears catch seals to eat on the ice.

北极熊在冰上捉海豹吃。

The Arctic is the home to about 25,000 polar bears.

北极是约两万五千只北极熊的家园。

Let's take action to protect our earth and save polar bears.

让我们采取行动来保护我们的地球，拯救北极熊。